The goal of this Career Development Program is to develop a new generation of pediatric endocrinologists who will be equipped to carry out innovative, scientifically rigorous patient-oriented and laboratory-based research related to diabetes mellitus in children. The need for this Program derives from the critical shortage of academic pediatric endocrinologists working in diabetes research, which has been emphasized by organizations such as the American Diabetes Association, Juvenile Diabetes Research Foundation, and Pediatric Academic Societies. In addition, this Program recognizes the important new opportunities for advancing diabetes research in children provided by such pivotal scientific advances as the Human Genome Project, and improved success in islet transplantation and the production of biomechanical and bio-engineered islets. This K12 Program will support Scholars for up to 3 years of research career development at the junior faculty level. The Program faculty includes 32 scientific mentors from the Children's Hospital and the U Penn School of Medicine who have outstanding credentials, active research programs and training records. These mentors will supervise Scholars' career development through basic laboratory and/or patient- oriented research related to diabetes in children. Career development opportunities will include 3 major areas of basic research 1) Signal Transduction: Mechanisms of Hormone Action; 2) Regulation of Pancreatic beta-Cell Function and Development; and 3) Genetic Approaches to Diabetes and Endocrine Diseases. Patient-oriented research opportunities will include the areas of 1) Islet Immunology, Transplantation, and Regulation; 2) Therapeutic Approaches to Islet Cell Preservation 3) Obesity and Insulin Resistance, 4) Diabetes Complications; and 5) Diabetes Epidemiology and Biostatistics. The Program includes a curriculum of formal training in all aspects of research; (including biostatistics, bioethics, molecular biology, etc.) and is strongly supported by access to a superb range of institutional resources, including the CHOP CTRC and the UPenn DERC.